Circuit breaker



June 17, 1947. PEEK 2,422,562

CIRCUIT BREAKER Filed May 15, 1942 3 Sheets-Sheet l wmqzsszs; INVENTOR441, Henry L. Peak.

June 17, 1947. L K 2,422,562

0 IRCUIT BREAKER Filed May 15, 1942 5 Sheets-Sheet 2 WITNESSES: INVENTORBY a 7 ATTORNE Henry L. Peak. I

June 17, 1947. H. L. PEEK CIRCUIT BREAKER Filed May 15, 1942 3Sheets-Sheet 3 INVENTOR Henry L. Peek 4 W ATTORN WITNESSES:

Patented June 17, 1947 CIRCUIT BREAKER Henry L. Peek, Edgewood, Pa.,assignor to Westinghouse Electric Corporation,

East Pittsburgh,

Pa., a corporation of Pennsylvania Application May 15, 1942, Serial No.443,040

6 Claims.

The invention relates to circuit breakers and more particularlyautomatic reclosing circuit breakers of the type which are adapted to bequickly reclosed upon the initial opening thereof by fault conditions inthe circuit.

In order to obtain quick reclosing of a circuit breaker, it i desirableto initially trip the breaker in response to a. fault condition by anon-tripfree tripping means which leaves the breaker operativelyconnected to the closing means, or under the immediate control of theclosing means, so that reclosing movement can be initiated immediatelyafter the circuit is interrupted and before the breaker reaches the fullopen position. This is permissible, however, only when the closing meansis in deenergized condition and will not retard opening of the breaker.If the fault condition is present when the circuit breaker recloses thecircuit it is very important that the breaker be tripped by trip-freetripping means free of the closing means so that opening of the breakerwill not be retarded or prevented by the closing means which is usuallyin energized condition at this time.

The present invention has for an object the provision of an improvedcircuit breaker operating means wherein tripping of the breaker inresponse to a fault condition is effected only by a non-trip-freetripping means if the fault condition occurs at any time when theclosing means is in deenergized condition, and is effected by a tripfree tripping means if the fault condition occurs at a time when theclosing means is in energized condition.

Another object of the invention is the pro-vision of a circuit breakerhaving a trip-free tripping means, a non-trip-free tripping means, andan improved automatic trip selecting arrangement responsive to thecondition of the closing means for selecting which of the tripping meansshall be effective to trip the breaker in response to a fault condition.

Another object of the invention is the provision of a circuit breakerhaving a fluid pressure or gas pressure operated closing means, atrip-free tripping means, a non-trip-free tripping means and anautomatic trip selecting device responsive to the condition of theclosing means for causing tripping of the breaker in response to a faultcondition to be effected only by the non-trip-free tripping means if thefault condition occurs at any time when fluid or gas pressure in saidclosing means is below a predetermined value, and by said trip-freetripping means if the fault condition occurs when fluid pressure in saidclosing means is above said predetermined value.

Another object of the invention is the provision of a circuit breakerhaving a trip coil operable to cause tripping of the breaker free of theclosing means, a second trip coil operable to cause tripping of thebreaker while leaving the breaker operatively connected to the closingmeans, and an automatic selector switch operative in accordance with thecondition of the closing means for selecting which of said trip coilsshall be operated in response to a fault condition in the circuit.

Another object of the invention is the provision of a circuit breakerhaving a fluid pressure operated closing means, a trip-free trip coil, anon-trip-free trip coil, and a fluid pressure operated selector switcheffective when the fluid pressure in said closing means is below apredetermined value to connect only the non-trip-free trip coil to afault responsive energizing circuit and operative by fluid pressure whenfluid pressure in said closing mean is above said predetermined value toconnect said trip-free trip coil to the fault responsive energizingcircuit.

Another object of the invention in accordance with a modificationthereof is the provision of a circuit breaker having a trip-free andnon-trip free tripping means and an automatic trip selecting switcheffective when the closing means is in deenergized condition to connectonly the trip coil of the non-trip-free tripping means to the faultresponsive energizing circuit, said selector switch being operated byclosing movement of the breaker to connect the trip coil of the tripfreetripping means to the fault responsive energizing circuit.

Another object of the invention is the provision of an improved circuitbreaker operating mechanism operable to quickly open the breaker at alltimes and that is capable of quickly reclosing the breaker upon theinitial opening thereof by a faultcondition.

The novel features that are considered characteristic of the inventionare set forth in particular in the appended claims. The structure andoperation of the invention together with additional objects andadvantages thereof will be best understood from the following detaileddescription of several embodiment thereof when read in conjunction withthe accompanying drawings, in which:

Figure 1 is a schematic view, partly in section, of a circuit breakerembodying the features of the present invention;

Fig. 2 is a plan view of the operating mechanism shown in Fig. 1;

Fig. 3 is a view of the operating mechanism shown in Fig. 1 with theparts shown in the tripped open position immediately following atripping operation by the trip-free tripping means; and

Fig. 4 is a schematic view, partly in section, of a. circuit breakerembodying a modification of the invention,

In order to simplify the drawings, some of the a a) parts of theoperating mechanism have been shown schematically.

Referring to Figures 1 and 2 of the drawing, the reference numeral 9indicates generally a metal casting which is formed to provide anoperating cylinder Ii and a plate |3 which closes the upper end of theoperating cylinder and forms a support for the various parts of themechanism. An operating piston |5 adapted to be operated by fluidpressure, such as compressed air, is reciprocally movable in thecylinder I and this piston together with the cylinder constitutes afluid motor or closing means for closing the circuit breaker. The lowerend of the operating cylinder ii is closed by a closure l1 secured inany suitable manner to the cylinder.

Mounted on the plate I3 is a lever mechanism of the trip-free typecomprising a closing lever 25 pivoted on a fixed pivot at its right-handend, and a breaker lever 23 pivoted at its left-hand end to the free endof the closing lever 2!. The closing lever consists of a pair of spacedparallel levers 25 (Fig. 2) which have their right-hand ends pivoted ona pair of aligned pivot studs 2? carried by spaced vertical plates 29secured to the plate H3. The breaker lever 23 also consists of a pair ofspaced parallel levers 3| (Fig. 2) pivoted at their left-hand ends on apivot pin 33 carried by and connecting the free ends of the levers 25.The breaker lever 23 is movable into the space between the outer levers25 which form the closing lever 2!, and the right-hand end of thebreaker lever carries a trip-free roller 35 which is mounted on a pincarried by and connecting the free ends of the inner levers 3| whichform the breaker lever,

The circuit breaker may be of any suitable construction either of theliquid or air break type and is shown schematically in Fig, 1 ascomprising stationary main and arcing contacts 31 and 39 and a movablebridging contact assemblage M which consists of a main bridge contact 43and a pair of spring biased arcing contacts 45. The arcing contacts arearranged to engage prior to the main contacts during closing of thecircuit breaker and to separate after separation of the main contactsduring opening of the breaker. The movable contact assemblage is carriedby a rod which is connected to the mid-portion oi the breaker lever 23through the agency of a pivoted lever A? and an operating rod 9, thelower end of the operating rod is being pivotaliy connected to thebreaker lever by a pivot pin 5% which extends between the inner levers3| which comprise the breaker lever 23. The circuit breaker is biased toopen position by an opening or accelerating spring 53. It will beunderstood that the circuit breaker may be of any conventional type andhave any suitable form of contact means.

The breaker lever 23 is biased upwardly by the opening bias of thecircuit breaker and the trip free roller 35 carried by the free end ofthe breaker lever 23 is normally engaged and releasably held in aposition of alignment with the fixed pivot axis 2'! of the closing lever2| by a trip-free latching means comprising a latch 55 pivoted on apivot pin 57 supported by the plates 29. When the trip-free roller 35 isheld in latched position by the latch 55, the breaker lever 23 isoperatively connected to the closing lever ii for movement thereby. Theclosing lever 2| is connected to the operating piston l5 of the closingmeans by a pair of connecting links 58 and by a connecting rod 89 whichextends into the cylinder through a fluid tight opening in the head ofthe cylinder.

The free end of the closing lever 2| is adapted to be releasably held inclosed position, as shown by the full lines in Fig. l, by anon-trip-iree latch means comprising a latch 53 pivoted on a fixed pivotpin 6| supported by a pair of spaced plates 62. The latch 59 is adaptedto engage a roller 63 on the pin 33 at the free end of the closinglever, The closing lever 2| is biased in a clockwise direction about itsfixed pivot axis 27 by means of a pair of helical retrieving springs 55which are disposed between each of the outer levers 25 and the supportportion l3.

When the trip-free roller 35 on the free end of the breaker lever 23 isreleased by a releasing operation of the latch 55, the operativeconnection between the circuit breaker and the piston I5 of the closingmeans is released and the breaker is moved to open circuit position at ahigh speed by the accelerating spring 53, free of any restraint by theclosing means. The opening movement of the circuit breaker causes thebreaker lever 23 to rotate in a counterclockwise direction toward theopen position as shown in Fig. 3, about the pivot pin 33 which is helddown by the non-trip-iree latch 59. The breaker lever 23 during aportion of its opening movement efiects an automatic releasing operationof the non-tripfree latch 58 to thereby release the free end of theclosing lever 2! to permit retrieving of the mechanism. For thispurpose, the breaker lever 23 has a projection 67 adjacent its pivotedend which during a portion of the opening movement of the breaker lever23 engages and rotates the non-trip-free latch 59 to released positionthereby releasing the free end of the closing lever 2|. When the freeend of the closing lever 2| is thus released, the retrieving springs 65rotate the closing lever in a clockwise direction about its fixed pivotaxis 2i and this movement of the lever 2| effects a clockwise rotationof the breaker lever 23 about the pivot pin 5i as a center to therebyreturn the trip-free roller 35 into latching engagement with the latch55. At this point, the breaker is in full open position and the twolevers 2| and 23 are latched together so that the breaker lever is thusagain operatively connected to the closing lever 2| and through the sameto the operating piston i5 of the closing means.

When the closing means i energized, that is, when compressed air isadmitted to the upper end of the operating cylinder II, the operatingpiston |5 is moved downwardly and rotates the two levers 2i and 23together in a counterclockwise direction about the fixed pivot axis 21to the closed position shown by the full lines in Fig. 1, therebyefiecting closing of the circuit breaker. When the two levers reachclosed position, the roller 63 is reengaged and latched by thenontrip-free latch 59.

The circuit breaker may also be tripped open by a releasing operation ofthe non-trip-free latch 59. This allows the circuit breaker to be movedto open position by its accelerating spring thereby causing the twolevers 2| and 23 to rotate in a clockwise direction about the fixedpivot axis 21 to the open position. In this instance, however, thecircuit breaker remains operatively connected to the closing lever 2|and through the same to the operating piston l5 of the closing means sothat the circuit breaker can be reclosed instantly, preferably from someintermediate open position after the arc is extinguished and before thecontacts reach full open position. This quick reclosing operation isinitiated by admitting compressed air to the upper end of the cylinder Hat an intermediate point in the opening movement of the breaker so as toinitiate the reclosing movement before the breaker reaches full openposition. The two levers 2| and 23 are shown in a partly open positionby the dot-dash lines in Fig. 1 after having been tripped by the latch59.

Compressed air for moving the operating piston I5 downwardly to close orreclose the circuit breaker is supplied from an auxiliary air reservoirtank "II. The auxiliary tank II is connected to a main air storage tank(not shown) in which compressed air is stored and maintained by asuitable motor driven compressor unit (not shown). The supply ofcompressed air to the upper end of the operating cylinder I I iscontrolled by an inlet valve mechanism shown sche matically at I3. Thevalve mechanism 13 is biased to a closed position in which the valveshuts off the supply of compressed air and at the same time connects theupper end of the operating cylinder II to atmosphere through anatmosphere exhaust port. The inlet valve is adapted to be operated toopen position to admit compressed air to the upper end of the cylinderII upon energization of the electromagnet I5 which controls the valve.The valve mechanism may be of any suitable construction but ispreferably similar in construction to the inlet valve mechanismdisclosed in the copending application of J. M. Cumming and R. C.Cunningham Serial No. 410,686,

filed September 13, 1941, now Patent #2,408,199, issued September 24,1946, and assigned to the assignee of the present invention.

The trip-free latch 55 is biased to latch position by a spring I! and isadapted to be operated to released position to release the breaker lever23 upon energization of a trip coil or tripping solenoid '19 which ismounted on the sup port I3 beneath the latch 55. The tripping solenoidI9 comprises a movable core 8| and an energizing winding 83 for movingthe core upwardly when the winding is energized. The movable core 8| isbiased downwardly to its lowermost position by a relatively lightbiasing spring 85 and the core carries a plunger 87 which is adapted toengage and move a projection 89 of the latch 55 to effect releasemovement of the latch upon en.. ergization of the tripping solenoid I9.The nontrip-free latch 59 is biased to latchin position by a spring 90and is adapted to be operated to released position to release theclosing lever 2| upon energization of a tripping solenoid 9| which ismounted at the left-hand end of the supporting plate I3 beneath thenon-trip-free latch 59. The tripping solenoid 9| is similar inconstruction to the tripping solenoid I9 and comprises a movable core'93 and an energizing winding 95 for moving the core upwardly when thewinding is energized. The core 93 is biased downwardly by a relativelylight spring 91 and the core has a plunger 99 which is adapted to engageand move a projection lfil of the latch 59 to move the latch to releasedposition upon energization of the tripping solenoid. Suitable stops areprovided to prevent movement of the latches 55 and 59 beyond theirlatching positions. Although each of the latching means 55 and 59 hasbeen shown as a single latch, it is to be understood that each of thelatching means in actual practice may be constructed in the form of adouble latch comprising a main latch and an auxiliary holding latchsimilar to the latching means disclosed in the aforementioned copendingapplication of J. M. Cumming and R. C. Cunningham, Serial No.

The circuit breaker is adapted to be automatically tripped open upon theoccurrence of predetermined abnormal conditions in the circuitcontrolled by the breaker, for example, in response to fault conditionssuch as overloads or short circuits. Automatic tripping of the breakerin response to these predetermined fault conditions is initiated by theoperation of a fault responsive relay indicated generally at I03 which,when operated, completes an energizing circuit for the tripping means ofthe mechanism. Electrical energy for energizing the tripping solenoidsis derived from auxiliary supply lines I95 and H11.

If an overload or fault condition occurs in the circuit controlled bythe breaker when the breaker has been standing closed and the closingmeans is in deenergized condition, that is, when there is no compressedair in the operating cylinder I I, it is desirable that the circuitbreaker be tripped only by the non-trip-free tripping means ornon-trip-free latch '59 because when the breaker is tripped by thislatch, it is moved to open circuit position Without releasing theoperative connection between the breaker and the closing means. Thispermits the circuit breaker to be reclosed in the shortest possibletime. The closing means is preferably energized at a predeterminedintermediate point in the opening movement of the breaker, that is,compressed air is admitted to the cylinder II at a predeterminedintermediate point in the opening movement of the breaker so as toinitiate the reclosing movement before the breaker reaches iull openposition, preferably to initiate the reclosing movement at a timeshortly after the current arcs drawn by the contacts have beencompletely extinguished. These quick reclosing operations may beaccomplished by energizing the inlet valve controlling electromagnet I5by a control circuit similar to that disclosed in the aforementionedcopending application of J. M. Cumming and R. C. Cunningham Serial No,410,686. However, if the overload or fault condition occurs at a timewhen the closing means is in energized condition, that is, when there iscompressed air in the cylinder II above the operating piston I5, it isvery important that the breaker be tripped open by means of the tripfreetripping means, that is, by the latch 55, in order to permit high speedopening of the breaker unretarded by any opposing force of the closingmeans.

In accordance with the invention, an automatic trip selectingarrangement is provided which causes the tripping operation of thebreaker in response to predetermined fault conditions to be effectedonly by the non-trip-free tripping means if the fault or overloadcondition occurs at any time when the closing means is in deenergizedcondition, and is operative to cause tripping of the breaker by thetrip-free tripping means if the fault or overload condition occurs whenthe closing means is energized, that is, when there is any compressedair in the cylinder I I above the operating piston I5. The tripselecting means comprises an automatic trip selecting switch I69 whichis operative in accordance with the condition of the closing means toautomatically select which of the two tripping solenoids is and 9| willbe energized in response to a fault condition.

The automatic trip selecting switch I09 comprises a pair of backcontacts III and a pair of front contacts II3 adapted to be selectivelybridged by a movable bridging contact H5. Referring now to the circuitconnections of the tripping circuit, the lower terminals of the trippingsolenoids l9 and 9! are connected, respectively, by conductors H4 and H6and by a common lead or conductor ill to the auxiliary supply line H35.An auxiliary switch H9 operated by the circuit breaker is connected inseries in the common lead or conductor I H, and this auxiliary switch isclosed when the breaker is in closed position and is open when thebreaker is open. The upper terminal of the trip-free tripping solenoidI9 is connected by a conductor l2! to the left-hand front contact H3 ofthe selector switch We. The upper terminalof the non-tripfree trippingsolenoid 91 is connected by a con ductor I23 to the left-hand backcontact ill of the selector switch. The right-hand front and backcontacts ii! and H3 of the selector switch are connected together and bya common lead or conductor M5 to one of the contacts I21 of the faultresponsive relay H13. The other contact of the fault responsive relay isconnected by a conductor 529 to the supply conductor I01. A manuallyoperable push-button switch I3! is provided for manually tripping thecircuit breaker and this switch is connected in series in a conductorI33 for connecting the upper terminal of the tripping solenoid 19 to thesupply conductor lfl'l. Closing of the manual push-button switch 53!serves to energize only the tripping solenoid '59 so that the breaker isalways tripped free of the closing means when tripping is initiated bythe manual push-button switch I3 I.

The automatic trip selecting switch H39 in the embodiment of theinvention shown in Fig. 1 of the drawing is controlled by a small airpressure operated piston L35 responsive to the air pressure conditionsin the main circuit breaker operating cylinder H. The piston 35 isconnected to the movable bridging contact I 5 of the selector switch andis reciprocably movable in a cylinder lSl secured to the top or" thesupporting plate !.3.over the operating cylinder 5. The lower endof thesmall cylinder communicates with the interiorof the upper end of thecylinder by means of an air passage 135} formed in the portion i3 of thecylinder casting E. A helical spring Mldisposed in the cylinder i3?between the piston l-35and the head of the cylinder l3! biases thepiston to its lowermost position to bias the movable bridging contact H5or the selector switch into engagement with the back contacts Hi. Theselector switch occupies this position at all times when there is nocompressed air in the main circuit breaker operating cylinder ii, thatis to say, when the closing means of the breaker is in .deenergizedcondition.

In this normal position of the trip selecting switch I03, it connectsthe non-trip-free tripping solenoid 9! to the energizing conductorthrough the back contacts iii of the selector switch and at the sametime disconnects the tripfree tripping solenoid'le from the energizingconductorlZEsince the front contacts i E3 of the trip selecting-switchare in open position. ,If an overload or fault condition occurs in themain circuit when the trip selecting switch is in this normal position,the operation of the fault responsive relay Ifl3 will cause energizationof only the nontrip-freetripping solenoid 9i so that the circuit breakerwill be tripped only by operation of the non-trip-free latchfifi leavingthe breaker operatively connected to the closing means. The breakor can,therefore, bequickly reclosed byinitiating the reclosing movementthereof before the circuit breaker reaches full open position.

When compressed air is admitted to the upper end of the breakeroperating cylinder l l for closing or reclosing the circuit breaker,compressed air is simultaneously admitted to the lower end of the tripselecting switch operating cylinder l3! through the passage l39 therebycausing the selector switch operating piston 135 to be moved upwardly toclose the front contacts H3 of the selector switch and open the backcontacts H I. The trip selecting switch 169 remains in this operatedposition as long as there is any substantial amount of compressed air inthe circuit breaker closing means. In this operated position of the tripselecting switch H19, it serves to connect the trip-free trippingsolenoid 19 to the energizing conductor I2 5 through the front contactsH3 ,of the trip selecting switch and at the same time maintainsthecircuit of the nonrtrip free tripping solenoid 9! open at the backcontacts ii! .of the trip selecting switch. Consequently, if an overloador fault condition occurs in the main circuit when the trip selectingswitch i119 is in its upper operating position, the operation of thefault responsive relay [D3 will cause energization of the trip-freetripping solenoid 19 so that the circuit breaker will .be tripped freeof the operating piston i5 of the closing means and will be movedquickly to the open position irrespectiveof the energized condition oftheclosing means.

The operation of the circuit breaker is briefly as follows: Assuming thecircuit breaker to be in the closed and latched position, as shown inFig. 1, and the closing means indeenergized condition with no compressedair in the'operating cylinder ll above the piston It, the automatic tripselecting switch 109 will be in the normal position, as shown in Fig. 1,with the movable contact H5 thereof bridging the back contacts .I H. It.anoverload or fault cOnditiOnocCurs at any time when the mechanism isin thisdeenergized condition, the fault responsive relay I03 will closeits contacts 121 and complete an energizing circuit forthe non-trip-freetripping solenoid9 i. This energizing circuit extends from the supplyline ,lfi'i through conductor .129, contacts [21 of the fault relay,conductor l25, back contacts l i l of thetrip selecting switch 109,conductor i2,3, winding of the tripping solenoid 9|, and conductors H6and H1 to the supplyline H15. Energization of the tripping solenoid 9|moves the plunger 99 upwardly to actuate the non-trip-free latch 59 toreleased position, thereby releasing the connected left-hand ends ofthe. closing lever 2| and breaker lever'23. The circuit-breaker-is movedquickly toward open position by the accelerating spring 53 rotating theconnected levers 2i and 23 in a clockwise direction about the fixedpivot axis2l. .Quick automatic reclosing operation of the circuitbreaker is'initiateclbefore the breaker reaches full open positionbyadmitting compressed air to the operating cylinder II at an intermediatepoint in the openingmove nent of the breaker piston [5. .The compressedair quickly reverses the movementof the operating piston l5 and startsthe reclosing movement of theibreaker from some intermediate position byrotating the now connected-levers. Hand 23 in a counterclockwisedirection about the fixedpivot axis 21. If the overload or faultcondition has been cleared by theinterruption of the circuit, theclosing means returns the circuitbreakerto the fullyclosed position andthe roller 63 on the left-hand ends of the levers is returned to thefully latched position where it is reengaged by the latch 59. At thesame time that compressed air is admitted to the circuit breakeroperating cylinder II to initiate the reclosing movement, compressed airis also admitted to the lower end of the trip selecting switch operatingcylinder I31 and moves the piston I35 upwardly to open the back contactsIII of the selector switch and close the front contacts H3 therebyconnecting the trip-free tripping solenoid I9 to the energizingconductor I 25. The trip selecting switch I I25 remains in thisoperating position as long as there is any compressed air in the upperend of the operating cylinder II. If the overload or fault condition isstill present at the time the arcing contacts of the circuit breakerreclose the main circuit, the fault responsive relay I03 will again beoperated to close its contacts I21. Since at this time the tripselecting switch is in its upper operating position, the trip-freetripping solenoid I9 will be immediately energized over a circuitextending from the supply conductor I01 through conductor I29, contactsI21 of the fault relay I55, conductor I25, front contacts II3 of thetrip selecting switch I05, conductor IZI, winding 83 of the trip-freetripping solenoid I9 and conductors H4 and II! to the supply conductorI55. The energization of the tripping solenoid 79 causes the tripplunger 81 to move the trip-free latch 55 to released position therebyreleasing the tripfree roller 35 carried by the free end of the breakerlever 23. The circuit breaker will, therefore, be quickly moved to openposition by its accelerating spring, free of the operating piston I5,that is, irrespective of the energized condition of the closin meanswhich is still energized at this time. The operating piston I5 continueson to the lowermost closed position at which time the supply ofcompressed air is shut off by the inlet valve 13 and the compressed airabove the operating piston I5 is exhausted to atmosphere through theexhaust port of the inlet valve 13.

As soon as the compressed air is exhausted from the cylinder II, thetrip selecting switch I99 is returned to its lowermost or normalposition by its biasing spring I II. This position of the parts isilustrated in Fig. 3 of the drawings. When the breaker lever 23 is inopen position as illustrated,

the projection 6'! thereof has operated the nonr trip-free latch 59 toreleased position and the free end of the closing latch 2| is releasedthereby. The retrieving springs 65 thereupon move the closing lever 2Iin a clockwise direction about the fixed pivot axis 21. This movement ofthe closing lever returns or retrieves the breaker lever 23 in aclockwise direction about the pivot pin 5I, returning the trip-freeroller into latching engagement with the trip-free latch 55. The twolevers 2| and 23 are new again operativey connected together and are inthe full open position so that the mechanism is operative to close thebreaker when the closing means is energized.

A modification of the invention is illustrated in Fig. 4 of thedrawings. In accordance with this modification of the invention, anautomatic trip selecting switch, indicated generally at I5I, is providedfor automatically selecting which of the two tripping means shall beeffective to trip the breaker. The automatic trip selecting switch I5Icomprises a pair of back contacts I53 and a pair of elongated frontcontacts I55 of the slide type, and a movable bridging contact I51 forselectively bridging the front or back contacts of the switch. Themovable bridging contact I5! is carried by a rod I59 which is biaseddownwardly by gravity or a light biasing spring (not shown) so as tonormally maintain the bridging contact I5! in engagement with the backcontacts I53. The right-hand front and back contacts are connected tothe energizin conductor I 25 and the other back contact I53 is connectedto the conductor I23 leading to the upper terminal of the non-trip-freetripping solenoid 9|. The left-hand front contact I55 is connected tothe conductor I2! leading to the upper terminal of the trip-freetripping solenoid "I9. The automatic tripping selecting switch I5I isadapted to be operated mechanically to its upper position to open theback contacts I53 and close the front contacts I55, by the closingmovement of the circuit breaker and is maintained in its upper operatedposition for a predetermined time interval by a dashpot device IGI. Inorder to actuate the selector switch I5I by the closing movement of thecircuit breaker, there is provided an actuating lever I63 which ispivoted intermediate its ends on a fixed support. The left-hand end ofthe actuating lever is disposed beneath the lower end. of the rod I59 ofthe selector switch and engages the rod. The right-hand end of theactuating lever I63 is formed to provide a pawl I55 which cooperatesWith ratchet teeth I61 provided on the breaker operated rod 49 or somepart movable with the breaker. The remaining structure of the circuitbreaker and operating means is identical to that of the originalembodiment and the corresponding parts have been indicated by the samereference characters.

When the circuit breaker has been standing in the closed position andthe closing means is deenergized, that is, when there is no compressedair in the circuit breaker operating cylinder II, the trip selectingswitch I5I is maintained in the normal position shown in Fig. 4, inwhich it connects the non-trip-free tripping solenoid 9| to theenergizing conductor I25 through the back contacts I53 of the selectorswitch. If an overload or fault condition occurs at this time, theoperation of the fault responsive relay I93 will cause energization ofthe non-trip-free solenoid 9! only, thereby tripping the breaker bymeans of the non-trip-free latch 59 which leaves the breaker operativelyconnected to the closing piston I5. This permits the circuit breaker tobe quickly reclosed by initiating the reclosing movement thereof beforethe breaker reaches full open position. Closing or reclosing movement ofthe breaker, however, causes the ratchet teeth It? to rotate theactuating lever I63 in a clockwise direction thereby moving the tripselecting switch I5I to its upper operating position, in which it opensthe back contacts I53 and closes the front contacts I55. The tripselecting switch I 5| is maintained in this upper operating position fora predetermined time interval after the operation thereof, the timeinterval being of suificient length to maintain the switch in its upperoperated position until after the breaker operating piston I5 hascompleted its closing movement and the compressed air has been exhaustedfrom the upper end of the operating cylinder. In this upper actuatingposition, the trip selector switch I5I connects the trip-free trippingsolenoid 79 to the energizing conductor I25 through the front contactsI55 of the selector switch so that if an overload or fault conditionoccurs at this time, the operation of the fault relay I53 will completethe energizing circuit for the trip-free tripping solenoid "I9 andthereby cause the breaker to be tripped free of the closing means by thetrip-free latch 55. lhus if the overload or fault condition is stillpresent at the time the circuit breaker recloses the circuit, thebreaker will be immediately tripped free of the closing means in thesame manner as in the original embodiment. The breaker will also betripped free of the closing means on a normal closing operation if anoverload or fault condition exists at this time.

It will thus be seen that in both embodiments of the invention, the tripselecting arrangement makes the circuit breaker mechanism non-tripireeat any time when the closing means is in deenergized condition, andtrip-free whenever the closing means is in energized condition.

While the invention has been disclosed in accordance with the provisionsof the patent statutes, it is to be understood that various changes inthe structural details and arrangement of parts thereof may be madewithout, departing from some of the essential features of the invention.It is desired, therefore, that the langauge of the appended claims begiven the broadest reasonable interpretation permissible in the light ofthe prior art.

I claim as my invention:

1. In combination, a circuit breaker, closing means for closing saidbreaker, trip-free tripping means for effecting opening of said breakerirrespective of the energized condition of said closing means,non-trip-free tripping means for eflecting opening of said breaker onlywhen said closing means is deenergized, means for operating saidtripping means, and a device effective whenever the breaker is in closedposition to prevent operation of said trip-free tripping means, saiddevice being mechanically operated by the breaker upon closing movementof said breaker to permit operation of said trip-free tripping means.

2. In combination, a circuit breaker, closing means for closing saidbreaker, trip-free tripping means for effecting opening of said breakerirrespective of the energized condition of said closing means,non-trip-free tripping means for effecting opening of said breaker onlywhen said closing means is deenergized, means for operating saidtripping means, device biased to a normal position in which it causesonly said non-tripfree tripping means to be effective, said device beingmovable to a second position in which it causes said trip-free trippingmeans to be effective, said device remaining in said normal positionwhen the breaker is in closed position, mechanical means operated by thebreaker during a closing movement thereof to operate said device to saidsecond position, and time delay means for maintaining said device insaid second effective position for a predetermined time interval afterit is moved to said second position.

3. In combination, a circuit breaker, closing means for closing thebreaker, trip-free tripping means having a trip coil operable whenenergized to cause opening of the breaker free of said closing means,non-trip-free tripping means having a trip coil operable when energizedto cause opening of the breaker, means for energizing said trip coils, aselector switch efiective when said breaker is standing in the closedposition to prevent energization of said trip-free trip coil, and amechanical device operated by said breaker during closing movement ofsaid breaker to operate said selector switch to permit energization ofsaid trip-free trip coil.

4. Incombination, a circuit breaker, closing means for closing saidbreaker, trip-free tripping means having a trip coil operable whenenergized to cause tripping of the breaker free of the closing means,non-trip-free tripping means having a trip coil operable when energizedto cause tripping of the breaker with the breaker remaining operativelyconnected to the closing means, means for energizing said trip coils,and an automatic selector switch normally effective to connect only saidnon-trip-free trip coil for energization by said energizing meanswhenever said breaker is in closed position, said selector switch beingoperated mechanically by closing movement of said breaker to connectsaid trip-free trip coil for energization by said energizing means.

5. In combination, a circuit breaker, a fluid motor operable to closethe breaker, a trip-free lever connected to said breaker, trip-freetripping means normally restraining one end of said trip-free lever,said trip-free tripping means including a trip coil operable whenenergized to release said one end of said trip-free lever and eiiectopening of the breaker free of said closing motor, a non-trip-iree leverconnected to said closing motor, non-trip-free tripping means normallyrestraining the other end of said trip-free lever and one end of saidnon-trip-free lever, said non-trip-i'ree tripping means including a tripcoil operable when energized to release said levers and eiiect openingof the breaker with the breaker remaining cperatively connected to theclosing motor, means for energizing said trip coils, said trip-freelever when released effecting release of the non-trip-free lever topermit retrieving of said trip-free lever, and means for selectivelydetermining which one of said trip coils is to be energized.

6. In combination, a circuit breaker, a fluid pressure operated motorfor closing said breaker, means comprising a trip-free lever and anontrip-free lever normally connecting said motor to said breaker,trip-free tripping means including a trip coil operable when energizedto permit movement of said trip-free lever independently of saidnon-trip-free lever and opening of said breaker free of said closingmotor, non-trip-free tripping means including a trip coil operable whenenergized to permit movement of both of said levers and opening of thebreaker with the breaker remaining operatively connected to the closingmotor, means for energizing said trip coils, and a selector switchresponsive to the position of the breaker when said breaker is in closedposition to connect said non-trip-free trip coil only for energizationby said energizing means, and means comprising a lever operated byclosing movement of the breaker for operating said selector switch toconnect said trip-free coil for energization by said energizing means.

HENRY L. PEEK.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,270,353 Spurck Jan. 20, 19422,150,584 MacNeill Mar. 14, 1939 2,150,587 Peterson Mar. 14, 19392,242,916 MacDonald May 20, 1941 2,292,096 Thumin et al. Aug. 4, 19422,319,645 Thumin May 18, 1943 2,261,929 Rippl Nov. 4, 1941

